If the average (arithmetic mean) of x, y, and 20 is 10 greater than the average of x, y, 20, and 30, what is the average of x and y?
A. 40
B. 45
C. 60
D. 75
E. 95
OA: E
A. 40
B. 45
C. 60
D. 75
E. 95
OA: E
bacali wrote:If the average (arithmetic mean) of x, y, and 20 is 10 greater than the average of x, y, 20, and 30, what is the average of x and y?
A. 40
B. 45
C. 60
D. 75
E. 95
OA: E
(x+y+20/3)-[(x+y+20+30)/4 ]=10
Solve for x and y
x+y=190
Arihmentic mean of x and y=(x+y)/2=95
IMO E
